Gypsum lumber



INVENTOR.

ATTORNEY.

C. F. DAVIS 2 Sheets-Sheet l CzlwP/rf/f flrVV/J ia; MW

GYPSUM LUMBER Original Filed March 18, 1931 Feb. 23, 1937.

C. F. DAVIS GYPSUM LUMBER Feb. 23; 1937;

Original Filed March 18, 1931 2 Sheets-Sheet 2 ATTORNEY.

Reissued Feb. 23, 1937 UNITED STATES GYPSUM LUMBER Clarke F. Davis,Short Hills, N. J., assign'or, by mesne assignments, to AmericanCyanamid & Chemical Corporation, a corporation of Delaware Original No.1,854,396, dated April 19, 1932,'Serial No. 523,523, March 18, 1931.Application for reissue April 14, 1934, Serial No. 720,653

11 Claims.

This invention reiates to a fire-resisting precast slab and to abuilding construction embodying the same. The principal object of theinvention is the pro- 5 vision of a structural unit having requisitestrength, desirable fire-resisting qualities, great flexibility in itsapplication, which may be cheaply and emciently produced and which maybe put 'to substantially all theuses for which a wooden 1o plank ofcorresponding size is now used.

In present day building construction there are many. types of floors androof decks ranging from wooden structures involving the use of plankingto poured-in-place concrete or gypsum construc- 15 tions having maximumfire-resisting qualities. There is a wide range in the relative costs ofthese various types of constructions, based not only upon the initialcost of production of the material, but dependent to a great extent upon5 the necessary manipulation in erection.

The present invention is designed to produce a cheap structural unitcapable of mass production, which is simple to erect, having all of thedesirable characteristics of wood planking, particularly as to its modeof application, its capability of being sawed, its ability to hold nailswithout cracking or spalling, being comparable thereto as to strengthand weight, while at the same time having the desirable characteristicsof 3 gypsum constructions. such as insulating value and fire-resistingqualities. To this end the invention contemplates the provision of astructural unit comprising a. framework of comparatively lightstructural metallic 35 members such as channels, with a poured, set bodytherebetween oi cementitious material such as gypsum, with suchadmixtures of fillers so as to be readily sawed and which will receiveand hold nails without cracking or spalling. Oppo- 40 site metallicstructural members are provided with mating joints such as tongues andgrooves respectively so th-at when assembled in place each structuralunit or precast slab will interlock with its neighbor and thusdistribute its 4.6 load and contribute to the strength of the entirestructure. In the preferred form, all four sides of the slab areprovided with these metallic members which, therefore, constitute theedge portions of the slab. Opposite members of each 60 pair are tonguedand grooved respectively, or otherwise mated, that is, the slab istongued and grooved both at its longitudinal sides and at the ends. Theinvention further consists in the novel ll arrangement, combination andconstruction of parts more fully hereinafter shown and described.

In the drawings Fig. 1 is a plan view of a slab of this inventionshowing portions oi others.

Fig. 2 is a fragmentary perspective view of two 6 slabs.

Fig. 3 is a partial plan-view oi! a joint between .three slabs.

Fig. 4 is an-elevation of a roof deck.

Fig. 5 is a plan view of a roof or floor construction.

Referring now with particularity to the embodiment illustrated, I haveshown a precast slab A having metallic structural members I and 2,constituting the longitudinal sides or edges of the slab, and members 3and 4 at the ends thereof. Each of these members consists essentially ofa channel having top and bottom flanges 5 and v 6 respectively overlyinga body I of set cementitious material poured between the structuralmembers. This cementitious material may be gypsum with or without anadmixture of about 3% of wood chips'as a filler, for the reason thatthis mixture is light, is readily sawed, may be nailed, sets quickly andhas the requisite strength.

The structural member i is provided with a longitudinal tongue shown at8, which may be formed in such a manner as to taper from the end towardthe vertical portion of the member I. The structural member 2 isprovided with a longitudinal groove 9 similarly tapered as in the case01' the tongue 8 and adapted to receive the tongue of the neighboringslab. In the same manner, the end structural element 3 is provided witha tongue Ill and the opposite end member [with a groove ll.

In some instances, it may be desirable to secure the various structuralmembers to each other at their abutting edges as by welding or the likeand in such case, this construction tends to contribute to rigidity tothe entire slab. This construction is not essential, however, as it hasbeen found that there need be no connection whatever between the seriesof structural members, but on the contrary they may have their endsadjacent each other and rely simply upon the bond between the interfacesthereof and the body of cementitious material to hold them in place.This bond is sufllcient for handling purposes and, of course,

when the various units are assembled into a building construction andthe mating portions interlocked, each slab is entirely supported at itsfour edges by its neighboring slabs and hence no other connection isnecessary, between the various structural members. Where desired,

however, one unit may be toe nailed to its neighbor.

In assembling the various units in a roof construction, for instance, itis not necessary that a special purlin or beam spacing be utilized. The

slabs being made in substantial sizes, for convenience approximatelyinches wide, 12 ft. long and 2 inches thick, they more than bridge thegap between ordinary roof or. floor supports. This provides averyconvenient form of roof or floor unit having a wide application to manycircumstances, termed constructional flexibility substantially twoinches thick, the beam spacing need not be closer than twenty-four timesthis dimension or 4 ft. on centers. In applying the units, they may, forinstance, be laid down from the peak toward the eaves or from wall towall on floors, regardless of purlin or beam spacings, and if thedistance between the peak and the eaves is greater than 12 ft., otherunits may be applied at' the end of the preceding units, the ends ofeach abutting and being interlocked and the excess length of the finalunit cut off as by means of a saw. The structural elements being ofcomparatively light gauge, they may be readily cut with a hack-saw orits equivalent, and a body of gypsum with an ordinary ice saw. Thissevered slab may then be used to begin the next row of units, whichcauses a break joint arrange-' ment, thus greatly increasing thestrength in this type construction. Due to the fact that this cut oflsection is supported at three sides by its neighboring slabs, it is noteven essential that it rest upon a purlin. Sufllcientstrength andsupport is contributed by the neighboring slabs to provide a strong andsatisfactory construction. This is principally for the reason that theinterlocked and tongued and grooved together metallic members constitutean I beam in which the extent of the vertical web is greater than thethickness of the base of the tongue.

Due to the fact that the body of gypsum may readily receive nails, nailsor spikes I! may be driven directly through the same into the beams orpurlins where they are of wood, or through the material and in proximityto the beams or purlins, where they are of metal, so that the protrudingend of the nail or spike may be clinched below the flange as at it. Ofcourse, in many cases, it will not be necessary to secure the slabs tothe purlins at all, but this may be done;-if desirable. In a roofconstruction, a nailing strip ll may be supplied in the wall ii to whichthe end slab may be nailed and thus assist in preventing slippase of theentire row of slabs. Due to the fact that the various tongues andgrooves are wedge-shaped and have great frictional contact with eachother, this end nailing may be dispensed with'entirely although it maybe used where desirable.

As clearly shown in the drawings, and particularly Fig. 2 thereof, thetongue and groove there shown are each wedge-shaped, and due to theirangularity have great frictional contact with each other. As shown,theplane of each face of the tongue and each face of the groove whenextended makes an angle less than 45 with the plane of one face of theslab. The fact that this angle is not greater than 45 prevents any tend-5 ency of the mated or interlocked members from slipping one on theother due to this great frictional contact when a load is appliedvertically to the upper face of'the mated slabs. If the angle inquestion was greater than 45 there 10 would be every tendency for oneface of the member constituting the groove to slip oil of thecorresponding face of that member constituting the tongue. For thisreason it is not ordinarily necessary to nail one slab to the other toprevent 15 separation of the two even under load.

A roof constructed as above may have applied thereto any of 'the varioustypes of waterproof rooflngs either in sheet form, which may be nailedor tacked directly to the body of gypsum, or the 20 slabs may be moppedwith tar or pitch. In the latter case, the interlocking, tongue andgroove constitutes a pitch stop and thus prevents leakage of the tar orpitch between the slabs.

It will be obvious that the same construction 25 may be used in thefloors of a building and that this arrangement may support any of thedesired type of floor finishes such as cinder fill, concrete, terrazzoor wood. In the latter case, the wood floor may be nailed directly tothe body of gypsum 3 material. 4

The slabs as above constructed are comparable as to cost, with woodplanking of the same thickness, and weigh only'slightly more, but stillbeing capable of being handled'by two men, as would be 35 required witha wooden plank of similar size. It

- may be put to the uses for which a wooden plank is now'adapted but inaddition it has insulating and fire-resisting qualities which make itfar superior to wood. Such a floor or roof construction has thedesirable characteristics of a gypsum precast slab or poured-in-placeconstruction but avoids many of the intricate operations necessary intheir erection. In addition, no grouting is necessary with such aconstruction. Also, as the slabs pass over purlins orbeams, they are notdependent upon the width of purlin 'or beam flanges for their support asare units which are adapted to extend only from beam to beam.

While the invention has been shown and described with reference to aspecific embodiment, obviously I do not wish to be limited thereto butthe invention is to be construed broadly and limited only by the scopeof the claims.

I claim: l. A precast slab of set plastic material having on all fouredges thereof metallic members, each of which is provided with ahorizontal flange substantially parallel with the top face of the slab,

- one pair' of members being tongued and the other ing wedge-shaped andof greater length than 7.

thickness.

3. A building construction comprising spaced apart supporting elements,precast slabs of set plastic. material supported thereon, said slabshaving longitudinal metallic edge members, said 7| members oi adjacentslabs being interlocked, some of said slabs being supported by at leasttwo of said supporting elements, the ratio of supporting element spacingto slab thickness being not lessthan 24:1.

4. A building construction comprising spaced apart supporting elementsand precast slabs of set plastic material supported thereon, said slabshaving metallic edge members, said members on adjacent slabs beingtongued and grooved together, in great frictional contact, some of saidslabs being of a length greater than the supporting element spacing, theratio of supporting element spacing to slab thickness being not lessthan 24:1.

5. A building construction comprising spaced apart supporting elementsand precast slabs of set plastic material supported thereon, said slabshaving metallic edge members, said members on adjacent slabs beingtongued and grooved together, the tongues and grooves being of greaterlength than thickness, the metallic members between slabs constitutingbeams.

6. A building construction comprising spaced apart supporting elementsand precast slabs of a set plastic material supported thereon, saidslabs having metallic edge members, said members on adjacent slabs beingtongued and grooved together, the tongues and grooves being of greaterlength than thickness, the metallic members between slabs constituting Ibeams, said I beams being at right angles to the supporting elements.

'7. A building construction comprising a; series of spaced apartsupporting elements, precast slabs having longitudinal metallic edgeportions supported thereon with their edges adjacent, said slabs havingtheir adjacent metallic edge portions tongued and grooved together, saidmetallic edge members together constituting an I beam in which theextent of the vertical web thereof is substantially greater than thethickness of the base of the tongue.

8. A precast slab of set plastic material having on its longitudinaledges metallic members, each of which is provided with a horizontalflange substantially parallel with the top face of the slab, one of saidmembers being tongued and the other member being grooved, said tongueand groove being of greater length than thickness.

' 9. A precast slab of set plastic material having on two opposite edgesthereof metallic members, one of which is tongued, the other beingcorrespondingly grooved, the plane of one face of the tongue and theplane of one face of the groove, when extended, making an angle lessthan 45 with the plane of one face of the slab.

10. A building construction comprising spaced apart supporting elementsand metallic edged slabs supported thereon, said metallic edge memberson adjacent slabs being tongued and grooved together, the plane of oneface of the tongue and the plane of one face of the groove, whenextended, making an angle less than 45 with the plane of one face of theslab, the ratio of supporting element spacing to slab thickness beingnot less than 24:1.

11. In a building construction, a plurality of preformed gypsum slabsarranged in a plane, each slab having on at least one pair of oppositeedges metallic members, said members having inwardly turned flanges inthe planes of the slab surfaces and forming edge reinforcements foropposite edges of each of said slabs, adjacent metallic members beingtongued and grooved together in a-tight frictional joint, and means forsupporting said slabs.

CLARKE F. DAWS.

